Super capacitors are usually referred to Electric Double Layer Capacitor, EDLC, as shown in FIG. 1, which includes components such as an electrode 1 containing a metallic current collector 2, a liquid or gel-like electrolyte 3, a separator 4 and a conductive pad 20. The EDLC can be rapidly charged and discharged through the charge adsorption effect of the electric double layer on the surface of the electrode. Super capacitors have a capacity as high as 1˜103 F or more. The charge and discharge power ratio of super capacitors is much higher than that of the secondary batteries (Lithium battery or lead-acid battery), and the level of transient output current of super capacitors is extremely high. However, the total storage capacity of super capacitors is inferior to secondary batteries. Super capacitors are applied primarily in electronic industry, followed by energy or green-energy industry and transportation industry. Super capacitors for commercial purpose have been successful for the past 30 years. However, the demand was low in early stage due to the high price. With the improvement in function and performance, lower price range, and fast increase of applications in the last decade, now is the best time to develop and produce super capacitors. Nevertheless, super capacitors currently on the market have problems such as high resistance, complex manufacturing process, and contain liquid or gel-like electrolytes.
TABLE 1Problems of super capacitors currently on the market.Currently knownItemsuper capacitorsProblemElectrodeActivated carbon,Insufficient conductivity.carbon black,Flat electrode, lower specificmetal-oxides,surface area.and conductivepolymericadhesives.ElectrolyteLiquid or gel-likePossess chemical toxicity, flammable,under roompotential leakage hazards, andtemperature.complex manufacture procedures.Water based orUnable to function under extremelyorganichigh or low temperature.electrolyte.Other partsSeparator, currentRequire metallic current collector duecollector,to insufficient conductivity of theconductive padelectrode.Require separator due to the usageof liquid or gel-like electrolyte.ManufacturingFactory layoutRequire expensive clean roomprocess andand equipmentand factory design.equipmentare expensiveRequire costly equipment toaccommodate the manufacture ofliquid or gel-like electrolyte.